The invention relates to a constant velocity universal ball joint for a wheel hub/universal joint unit with a bearing assembly arranged on the wheel hub and tensioned relative thereto by the outer joint part of the universal joint. The invention has an unfastenable connection between the wheel hub and universal joint which includes a bolt/nut assembly. The outer joint part and the inner joint part have longitudinally extending ball tracks which are arranged radially opposite one another and which contain torque-transmitting balls. The balls are held in one plane in individual windows of a ball cage positioned between the outer joint part and the inner joint part and which, upon articulation of the joint, are moved on to the angle-bisecting plane. The outer joint part, at one end, being closed by a base part and the inner joint part is connected to a shaft. Preferably, at least towards the shaft end, the ball cage is axially supported on inner faces of the outer joint part.
Joints for wheel hub/universal joint units are known from DE 36 18 130 C2, issued Jun. 29, 1989. It already describes advantageous designs in respect of the outer joint part tensioning the bearing assembly relative to the wheel hub and as far as means for transmitting torque between the outer joint part and the wheel hub are concerned. For this purpose, a projection of the outer joint part is provided with axial inner teeth which are engaged by corresponding outer teeth at the end of the wheel hub. The projection rests against the end faces of the inner bearing rings of the bearing assembly, which inner bearing rings, in turn, are supported on a step of the wheel hub. For tensioning purposes, a threaded bolt is used with a long shank, so that any settlement which may occur in the connection can be compensated for without causing any functional disadvantages.
The outer part of the joints used in this case is either designed to be integral with a formed-on base or it is provided with a base which is produced separately and formed in a form-fitting way. The base or base part is provided with a threaded hole for threading in the bolt.
The assembly of such joints is not characterised by any special features. The inner joint part and cage are inserted into one another by pivoting their axes by 90.degree. relative to one another, and they are then coaxially aligned relative to one another. Then, by pivoting their coaxially aligned axes by 90.degree. relative to the axis of the outer joint part, they are jointly inserted into the outer joint part. Subsequently, it is necessary to set an assembly angle between the inner joint part and outer joint part, which angle is greater than the respective maximum operating angle. The balls are individually inserted radially from the outside into the windows of the cage set to be positioned in the angle-bisecting plane, the windows emerging from the outer joint part. At the same time the balls are inserted into the tracks of the inner joint part and by pivoting the inner joint part back into the outer joint part, the balls are introduced from the end face into the tracks in the outer joint part.
For setting the assembly angle of the inner joint part and cage relative to the outer joint part in the way described above, it is necessary to provide the outer joint part with a free space near its axis. The space is used for assembly purposes only and it increases the axial distance between the joint center determined by the ball center plane E and the bearing assembly. To ensure that less space is required and to reduce the moments to be accommodated in the wheel hub/universal joint unit, it is desirable to reduce further the distance between the joint center and the bearing assembly.